Decoding 54:1 Triglyceride Fatty Acid Composition

Steps:

• 54:1 notation means three fatty acids with total 54 carbons and 1 double bond.
• Average 18 carbons per chain suggests all are C18 fatty acids.
• One double bond indicates one unsaturated C18:1 chain, leaving two saturated C18:0 chains.
• Table likely identifies the saturated component as C18:0.

Why D is correct:

• Saturated 18-carbon fatty acid (stearic acid, C18H36O2) fits as two of the three chains in 54:1, per lipid nomenclature for total carbons and bonds.

Why the others are wrong:

• A: 15 carbons too short; three C15 chains total only 45 carbons, not 54.
• B: 17 carbons uncommon and odd-numbered; doesn't sum to 54 with typical pairs.
• C: Unsaturated 18 carbons describes the oleic acid (C18:1) chain, not the saturated one identified.

Final answer: D